Clock



June 24, 1930.

P. BAUMGARTEN CLOCK Filed Jan. 28, 1926 2 Sheets-sheaf, 1

Jun 24, 1930.

' Filed Jan. 2a, 1926 P. BAUMGARTEN 1,768,100

CLOCK 2 Sheets-Sheet 2 v 8/ In venfar';

Patented June 24, 1930 PATENT OFFICE PAUL, BAUHGABTEN, OI" IBEBLIN-WILMEBSDOBF, GERMANY, ASSIGNOR 'IO ADOLF- BIESE, 01'. BERLIN, GERMANY CLOCK Application filed January 28, 1926, Serial No. 84,461, and in Germany January 81, 1825.

This invention relates to a clock with con. cealed driving mechanism, the novel feature of which consists in the fact that the hands are driven by means of rings concentric with the axes of rotation of the hands and located'co-axially one behind the other, the driving shaft carrying a bevel wheel and a worm wheel, of which the bevel wheel engages in the toothed minute ring and the worm wheel, with the interposition of an intermediate gear, enga es with teeth on the hour hand ring. In or er to simplify. the gear, the ratio of 1: 12 is selected as the ratio of transmission from the bevel wheel to the hand ring of the minute hand, so that for the clockwork mechanism the usual change speed wheels can be employed by approximately modif ing the connection to the minute wheel of t e clockwork movement.

, In order to hold the outer protecting glasses of the clock, one of which at the same time carries the dial figures, in their annular grooves or-in any other similar manner on the casing without special means, the hand shaft, upon which the hands are loosely guided in order that while bein revolved by the rings they may have a smal central hold in the middle of the axis, is utilized to hold together the outer glasses by means. of a stop on one side and a nut or a clamping piece on the other. It has been found that a particularly light and reliable track for the hand rings may be obtained by supporting the latter upon lugs or cams arranged eccentrically to the casing in such a way that they run downwards with a one-sided inclination in the direction of revolution so that to the rin with their whole weight, a comp etely uniform run is thereby imparted.

In order to prevent a rotation of the hand rings in the opposite direction, which might impair the smooth running .in the redetermined direction, the driving mem r is provided for one or both rings with a back lock, which only permits rotation in the prescribed direction. A small spring serves for lightly pressing both rings, or the ri coming laterally into contact with the drivbearing ing member. The pivot of the hands, which is readily carried round by the rotating hands, has a tendency also to carry round with it the outer mounted glasses. This tendency can be counteracted in a simple manner by the glasses resting with small notches or flattened parts on corresponding section respectively, the part of the mechanism associated wlth the hand rings;

In Fig. 5 is a hand shown both in front elevation and side elevation;

Fig. 6 is a view corresponding to Fig. 4, wherein the method of securing the glasses by means of the hand pivot is illustrated.

The case of the clock illustrated consists of an annual upper part 1, with a dial 2 made of glass, a hollow column 3, and a base or foot member 4, also hollow. In the base 4 is enclosed a small clockwork movement 5. To this clockwork movement is fitted a change-speed gear 6, from which a sleeve 7 receives its drive in such a manner that it completes one revolution in each five minutes.

This rotary movement is transmitted to a vertical shaft 8, which passes freely and,

rotatably through one or more intermediate flanges 9 within the column 3. Upon the upper end of the'sleeve 7 is provided for this purpose a slotted fork 10 and at the lower end of the shaft 8 a driver arm 11 engaging in the fork 10. n the upper end of the shaft 8 is a small bevel wheel 12 which engages in teeth 13 on a ring 14 which is so supported as to be freely rotatable in theupper art 1 of the casing in front of the dial 2 tween lugs 15.

Since the shaft 8 is revolved by the clockwork twelve times in one hour the toothed ring 13 must have twelve times as many teeth as the small bevel wheel 12, that is to say, 144 teeth for example if the latter has '12.

The minute hand 16 is mounted by its central aperture freely upon the pin 17 arranged in the center of the dial plate 2 and is secured by its bent end in a hole 18 bored in the minute ring 14.

The hour hand 19 is mounted in the same manner on the pin 17 of the dial plate and hooked by its bent outer end in a hole 20 bored in the hour ring 21, which is rotatably supported in front of theminute ring between similar lugs 22. The drivin of the hour ring is likewise effected from t e shaft 8, upon which, underneath the bevel wheel 12, a worm 23 is provided, which engages in a worm Wheel 24, with which a spur wheel 25 is connected, which in its turn meshes with teeth 26 on the hour ring 21. If the worm is single-threaded and the worm wheel 24 has twelve teeth, this worm wheel after twelve revolutions of the shaft 8, that is to say in one hour, will revolve once, so that if the spur wheel 25 has twelve teeth and the tothed ring 26 has 144 teeth the ring of teeth 26 and with it the hour ring 21 will execute one revolution in twelve hours.

Towards the outer sides the upper part 1 of the casing is preferably protected from dust and the like by glass plates or windows 27.

The arrangement described may be modified in its details as desired or required, and certain of the elements indicated may be replaced by other equivalent ones without the scope of the invention in itself being hereby exceeded. For example, instead of the minute ring and the hour ring, glass plates may be utilized, which, being rovided on the outside with the requisite toothed rings, would be mounted by corresponding apertures on the pin of the dial. The hands could in this case be etched in the plates, painted thereon. or even secured thereto in any convenient manner. Similarly the pitch of the worm and the numbers of teeth of the various (gears may under some circumstances be varie In the constructional form according to Fig, 6 the handshaft 17 carries on the efthand side a flange 17' which bears against the left-hand clock glass 27, while on the right-hand end of the shaft 17 is mounted a nut 17", also with a flan e or a washer, which presses the right-han clock glass 27 into the annular groove 1', as a result of which the two glasses 27 and 27 are in this way held in the corresponding grooves 1' of the case.

What I claim is 1. In a clock, a casing, a transparent plate fitted in said casing, clock hands, a shaft like member fixed to the plate and pivotally I mounting the inner terminals of the hands. and annular driving members connected with the outer extremities of the hands.

2. In a clock, a casing, transparent plates located in the casing, a shaft like member connecting the medial portions of the plates, clock hands having the inner terminals loosely mounted on the shaft like member intermediate the transparent plates, and annular driving members connected with the outer terminals of the clock hands.

In testimony whereof I have signed my name to this specification.

PAUL BAUMGARTEN. 

